The invention relates to a method for operating a navigation system of a motor vehicle. By means of an input device of the navigation system, an input is received, by way of which a destination is indicated. Then at least one conceivable route from a starting position to the destination is determined by an arithmetic device of the navigation system by means of filed map data. In addition, the invention relates to a navigation system, which is constructed for implementing such a method, as well as to a motor vehicle having such a navigation system.
Navigation systems for motor vehicles are known from the state of the art in multiple configurations. All navigation systems have in common that first the destination is to be defined in that, for example, a corresponding input is carried out by a user at an input device of the navigation system. The known navigation systems usually also have a navigation receiver, such as a GPS receiver, by means of which position signals are provided which characterize the respective momentary position of the motor vehicle. When the current geographical position of the motor vehicle is known (in geo coordinates), this geographical position can be matched by means of a so-called map-matching process with the location information or a road network of a digital road map. In this case, the measured geographical coordinates of the motor vehicle are imaged in the coordinate system of a digital map, so that the current position of the motor vehicle is determined on the digital map. When the current position on the map is known, by means of the navigation system, a route can be computed from the current position to the defined destination. In this context, many different methods are known, as to how such a navigation route can be computed. Thus, the user can, for example, define optimizing criteria, according to which the route to the defined destination is to be determined. In this respect, it is, for example, already the state of the art to choose between a “fast” route, on the one hand, and a “short” route, on the other hand. The user normally needs to make the corresponding adjustments with respect to the criteria once, so that the selection of the best possible route according to the specified criteria automatically takes place by the navigation system. Once the criteria have been defined, they can also be changed by the user at any time.
A navigation system is known, for example, from European Patent Document EP 1 085 297 A1, in which criteria defined by the user are taken into account when computing the navigation route.
A method for the route inquiry and the route guidance of motor vehicles by applying one or more locating methods is known from German Patent Document DE 196 11 915 A1. In this case, a mobile radio system is used consisting of mobile radio terminals and a mobile radio network. Upon a user inquiry, a route planning takes place in a central station, which is carried out according to specified optimizing criteria. An individual route description is generated in the central station and is transmitted to a terminal and processed there.
From German Patent Document DE 10 2009 047 395 A1, a method is known for controlling a hybrid drive of a vehicle, the hybrid drive having an electric drive and a fuel drive. A database is then provided, which has assignments between route information and first as well as second route criteria. The route information represents routes that can be driven by the vehicle, while the first route criterion represents a preferred use of the electric drive on the respectively assigned route, and the second route criterion represents a preferred use of the fuel drive on the respectively assigned route. With respect to a currently received route information, a current route criterion assigned to the current route information will then be determined from the database and control information will be provided, on the basis of which the electric drive is used when the current route criterion is the first criterion, or the fuel drive is used when the current route criterion is the second route criterion.
It is an object of the invention to improve the usability of a navigation system of a motor vehicle in comparison to the prior art.
According to the invention, this method is implemented by a navigation system as well as by a motor vehicle having the characteristic according to the respective independent claims. Advantageous embodiments of the invention are the object of the dependent claims, of the description and of the figures.
A method according to the invention is used for operating a navigation system of a motor vehicle. An input is received by means of an input device of the navigation system, by way of the input, a destination being indicated. This input can be carried out at the input device, for example, by a user who defines the destination himself. An arithmetic device of the navigation system then determines at least one conceivable route from a starting position to the destination by means of filed map data. According to the invention, it is provided that, for at least one route section of the at least one possible route, at least one parameter—for example, a reception strength or availability and/or a capacity utilization—of at least one wireless communication network provided on the route is determined by the arithmetic device; in particular, is determined ahead of time before the starting of a route guidance or navigation to the destination.
The usability or the acceptance of the navigation system with respect to the state of the art is therefore improved in that, for at least one route section of the determined conceivable route, and particularly for the entire conceivable route, the parameter—such as particularly the signal strength and/or a capacity utilization—of a least one wireless communication network is determined, for example, particularly of a mobile radio network. In this manner, it can, for example, be achieved for the final route guidance or for the navigation to the destination, to select that route by which the greatest availability of the at least one wireless communication network is provided. This may mean, for example, that a route can be selected for the route guidance which permits a relatively long utilization of the network without interruption and/or the network coverage is the largest. However, it is also possible to inform the user of the navigation system of the determined availability and/or capacity utilization of the communication network, so that the user is informed of the features of the communication network along the route.
Within the scope of the invention, a “communication network” is a wireless data transmission network, in the case of which data are transmitted at least unidirectionally—and particularly bidirectionally—according to an arbitrary specified data transmission standard and thereby a specified standardized communication protocol. Generally, the term “communication” may comprise a digital telephony and/or a—for example, packet-oriented—information transmission.
The determination of the at least one parameter means, in particular, that a spatial course of values of this parameter is determined along the at least one route section of the conceivable route. Preferably, a current value range of this parameter is determined in this case for the at least one route section, particularly the entire route. However, optionally, an anticipated value range of the parameter can be determined along the at least one route section for a later time period. For example, it can in each case be determined for a plurality of route sections of the route at which point in time the motor vehicle will probably be situated on the respective route section, and the arithmetic device can ahead of time determine of the parameter of the communication network for the respective route section at the determined point in time. This has the advantage that possibly existing network gaps can be determined early ahead of time.
Thus, the at least one route is determined from the starting position to the destination. In this case, for example, a current geographical position of the motor vehicle can be determined as the starting position by means of position signals of a navigation receiver, as, for example, by means of signals of a GPS receiver, thus, generally, of a satellite-based receiver. However, the starting position may also be defined by the user himself in that a corresponding input is carried out at the input device. Furthermore, it is also conceivable that that starting position is obtained by means of the arithmetic device from a digital calendar. Here, the arithmetic device can check by means of calendar data or appointment data in which geographical position of the motor vehicle will probably be situated at a certain point in time.
As mentioned above, a receiving strength of the communication network on the at least one conceivable route can be determined as a parameter by the arithmetic device. In addition or as an alternative, it may also be provided that a capacity utilization of the communication network on the at least one conceivable route is determined as a parameter by the arithmetic device. Both parameters represent a reliable measurement of the quality of the communication network, so that correspondingly a respectively optimal route can be selected on which, for example, a long and interruption-free telephoning is possible.
In an embodiment, it is provided that at least two mutually different conceivable routes are determined for a route guidance from the starting position to the destination and, in each case, for at least one route section of the routes, the at least one parameter of the wireless communication network is determined. As a function of a comparison of the respective routes with respect to the at least one parameter, one of the conceivable routes can then be selected for a navigation to the destination or for the route guidance by the arithmetic device. This means that the finally selected navigation route can be calculated or selected according to an optimizing criterion with respect to the signal strength and/or capacity utilization of the communication network, so that, for example, that navigation route is selected which has the best availability of the wireless communication network. When this route-optimizing criterion is activated, particularly interruptions of telephone calls can thereby be avoided, or situations are prevented in which important telephone calls are interrupted during the drive because of a lack of mobile radio reception or a large capacity utilization. In addition, it is thereby ensured that communication devices possibly present in the vehicle can communicate without interruption with central server devices if the same communication network is also used for this communication.
It may, for example, be provided that the user of the navigation system selects a route-optimizing criterion, according to which the final navigation route is to be optimized with respect to the availability and/or capacity utilization of the communication network. For example, such an optimizing criterion “interruption-free cell phone” can also be combined with another criterion, such as “fastest route” or “shortest route”. When the route-optimizing criterion concerning the availability of the communication network is selected, the arithmetic device can then select that route as the final navigation route which has the best availability of the wireless communication network.
However, it is also possible that the above-mentioned route-optimizing criterion concerning the at least one parameter is autonomously activated by the navigation system. This may take place, for example, when, by means of the filed data—for example, data of a digital personal calendar of the user—the navigation system detects that the utilization of the communication network by the user is intended during the drive, thus, for example, that the user intends to telephone during the drive.
An adjustment of the reception quality on the different routes can, on the one hand, take place by means of data of a digital calendar and, on the other hand, by means of the arithmetic device. By means of the calendar data, it can be determined at which point in time the driver probably intends to telephone, and respective route sections of the routes can be determined on which the motor vehicle would probably travel at this point in time. These route sections of the different route can then be compared with one another with respect to the at least one parameter, and that route can be selected on which the telephoning can take place without interruptions at the determined point in time. In this case, the planned length of the telephone calls may also be determined.
It may optionally also be provided that, after the selection of the final navigation route, the determined parameter—therefore particularly the reception intensity and/or capacity utilization—of the communication network is displayed on a display of the navigation system. In this manner, the user—particularly the driver—will be informed of the availability of the communication network on the suggested navigation route. Such a representation of the availability may be such on the display that the at least one parameter of the communication network is displayed in a map representation. For example, a route section of the route situated ahead may be provided with corresponding information concerning the reception strength and/or the capacity utilization of the communication network.
It is, however also possible to indicate the determined parameter of the communication network at the at least one possible route on the display even before a final navigation route is selected for the route guidance. Here also, the availability of the communication network can be displayed at the at least one possible route in a map representation. When the arithmetic device determines, for example, two different possible routes, which lead to the defined destination, these routes can be displayed on the display together with the information concerning the reception strength and/or the network capacity utilization of the communication network, so that the user can select one of the routes fir the route guidance. This embodiment is particularly advantageous when the route with the best network reception is clearly longer than other conceivable routes which do not have such a good network reception.
Here, the driver can decide himself whether he would rather like to select a shorter route with a poorer network reception or a longer route with a better network reception.
In an embodiment, it may be provided that, during a navigation to the destination or during the route guidance along an already selected navigation route, a communication device of the motor vehicle—such as a mobile radio device or telephone system—is activated by way of which a communication connection is established to the communication network. The establishing of this communication connection can then be detected by the navigation system, and, after the detection, the arithmetic device can check the at least one parameter, particularly the reception strength and/or the capacity utilization of the communication network with respect to a route section situated ahead. When the communication network is a mobile radio network, it can be checked by means of the calculation device whether or not a sufficient mobile radio reception will soon be available. In this manner, the user can be reliably assisted—for example, when telephoning.
When it is detected by the arithmetic device that, for example, the parameter on the route section situated ahead is in a specified value range, thus, for example, the signal strength is lower than a specified limit value, and/or capacity utilization is higher than a specified limit value, the arithmetic device can determine a current distance to this route section and/or a time before this route section will be reached, and can output it by means of an output device, particularly by means of a display. The user is thereby informed as to how long the communication connection will still be maintained. The user can thereby better prepare himself for an interruption of the communication connection. For example, he can thereby himself still terminate the current telephone calls before the interruption of the connection.
The determination of the reception quality of the communication network preferably takes place by means of a digital network coverage map of the communication network. By means of such a network coverage map, the parameter of the communication network can, on the one hand, be determined very reliably and precisely and, on the other hand, without many computing expenditures and mainly without additional measuring devices.
In this case, the network coverage map can be filed on a central, vehicle-external server device, so that the network coverage map will be available to a plurality of motor vehicles, which can communicate with the central server device. Therefore, a wireless communication connection can be established between the navigation system and the vehicle-external central server device, by which wireless communication connection at least a part of the digital network coverage map is transmitted from the server device to the navigation system. In this case, the selection of the required part of the map can take place as a function of the situation and according to the requirements, specifically as a function of the starting position—particularly the current position of the motor vehicle—and as a function of the destination, particularly as a function of the determined at least one conceivable route.
When the network coverage map is filed centrally on the server device, a so-called “crowd-sourcing” can also be carried out: A plurality of motor vehicles can in each case transmit data to the server device, which data contain information concerning the current position of the respective motor vehicle as well as concerning the current, particularly measured, value of the at least one parameter of the communication network at the respective motor vehicle. By means of these data, the network coverage map in the server device can always be updated, so that also time fluctuations of the network availability can be taken into account. A current and highly precise network coverage map is therefore always available.
The central server device can use the received data also for determining such a network coverage map ahead of time for a later time period. Specifically, by means of a statistical analysis of the data, time patterns (for example, course of the day) of the reception quality of the communication network can be determined, which can then be used for predicting the reception quality by means of the central server device. A network coverage map can thereby be provided which has a time-related dimension and in which information is therefore listed concerning the probable network quality.
A mobile radio network is preferred whose reception quality is determined on the at least one route section of the at least one conceivable road by means of the arithmetic device. Navigation routes can therefore be provided on which the driver can telephone without interruptions.
However, in addition or as an alternative, it may be provided that the reception quality of an ad-hoc network and/or of a public WLAN-network (Hotspot Network) is determined on the at least one route section. In this respect, it can also be provided that the arithmetic device determines whether the ad-hoc network or the public WLAN network has the better reception quality, so that, as required, an automatic change can be implemented between the two networks as a function of the reception strength.
Generally, it can also be provided that, for the at least one conceivable route, the reception features or the at least one parameter of at least two separate communication networks are determined by means of the arithmetic device. When at least two networks are present on the conceivable route, as required, a selection can be made between different communication networks as a function of the respective network quality.
A navigation system for a motor vehicle according to the invention is constructed for implementing a method according to the invention.
A motor vehicle according to the invention, particularly a passenger car, comprises a navigation system according to the invention.
The preferred embodiments introduced with respect to the method according to the invention and their advantages correspondingly apply to the navigation system according to the invention as well as to the motor vehicle according to the invention.
Further characteristics of the invention are contained in the claims, the figures and the description of the figures. All characteristics and combinations of characteristics indicated in the specification as well as the characteristics and combinations of characteristics indicated in the following in the description of the figures and/or illustrated only in the figures can be used not only in the respectively indicated combination but also in other combinations or alone.
The invention will now be explained in detail by means of a preferred embodiment as well as with reference to the attached figures.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawings.